<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <title>key的原理</title>
  <script src="../js/vue.js"></script>
</head>

<body>
  <div id="root">
    <h2>人员列表(遍历数组)</h2>
    <button @click.once="add">添加一个老刘</button>
    <ul>
      <li v-for="(p, index) in persons" :key="p.id">
        {{p.name}}-{{p.age}}
        <input type="text" />
      </li>
    </ul>
  </div>

  <script>
    Vue.config.productionTip = false

    new Vue({
      el: '#root',
      data: {
        persons: [
          { id: '001', name: '张三', age: 18 },
          { id: '002', name: '李四', age: 19 },
          { id: '003', name: '王二', age: 20 }
        ]
      },
      methods: {
        add() {
          const p = { id: '004', name: '老刘', age: 40 }
          this.persons.unshift(p)
        }
      }
    })
  </script>
</body>

</html>